单项选择题With the following CLI command output performed on an LNS: show l2tp session L2TP session 1 2 3 is up .What is the meaning of the numeric values in the output?()
A.session 1, destination 2, tunnel 3
B.destination 1, session 2, tunnel 3
C.tunnel 1, session 2, destination 3
D.destination 1, tunnel 2, session 3